PlatformNotSupportedException and System.DllNotFoundException: ws2_32.dll in 4.0.29

[Adrien-pierret]

Hello everyone,

While trying to build and/or run the projects I ran into 2 distinct issues: ・If I run the project using .NET Standard 2.0 I get a "PlatformNotSupportedException" ・If I change and run it with .NET 4.x I get a "System.DllNotFoundException: ws2_32.dll" and a "System.Windows.Forms.dll assembly is referenced by user code, but is not supported on Android platform. Various failures might follow." warning.

Both errors occur for the "InTheHand.Net.Bluetooth 4.0.29" package when i try to execute: BluetoothClient client = new BluetoothClient(); And they both happen on the phone and on the simulation.

Other info: ・I am running Unity 2020.3.33f1 ・OS: Ubuntu 20.04 ・Target: Android (Google pixel 4) ・The package was installed using Nuget for Unity

Best regards

[peterfoot]

I think the way that Unity manages NuGet platforms is different to Visual Studio which leads it to select the wrong dll. There is a monoandroid dll in the package which should work. You could try extracting it manually and referencing it directly. The .NET 4 dll is for Windows only hence the ws2_32.dll error, the .NET Standard dll has no implementation and simply acts as an API surface to be replaced with the correct runtime version. I will need to do some more testing with Unity to work out a fix.

[Adrien-pierret]

Thank you peter for such a quick answer. So I gave it a try and downloaded the package from "https://www.nuget.org/packages/InTheHand.Net.Bluetooth" I just took the dll from the monoandroid11 folder and added it to my plugins and Assets/Packages (not at the same time, on 2 different occasions). Now when I try to build I run into the following:

"ArgumentException: The Assembly Mono.Android is referenced by InTheHand.Net.Bluetooth ('Assets/Plugins/inthehand.net.bluetooth.4.0.29/InTheHand.Net.Bluetooth.dll'). But the dll is not allowed to be included or could not be found."

I tried to compile for Android 10; 11 and "highest available" in Unity. I Also tried both .NET 2.0 and 4.X. Same result. Am I missing something?

p.s: I am new to Unity and C# so I might have done something wrong. Sorry if I made some newbies mistakes.

[peterfoot]

I'm not a native to Unity either so don't know my way around all the differences with a regular .NET project. I've used it previously to test the Windows version of the dll, but not Android but it should work. I'll do some investigation...

[NicholasLimHongDa]

I have the same problem, here's the environment I used, ・Unity 2022.3.16f1 ・Dev OS: Windows 11 Home ・Target: Android (Google Pixel 7a) ・Package was installed using NuGet for Unity

I tried to do what @Adrien-pierret did, by manually extracting the "monoandroid10" dlls into the package. I got the following error, which is slightly different from the one @Adrien-pierret mentioned,

Assembly 'Assets/Packages/InTheHand.Net.Bluetooth.4.1.40/lib/monoandroid10/InTheHand.Net.Bluetooth.dll' will not be loaded due to errors: Unable to resolve reference 'Mono.Android'. Is the assembly missing or incompatible with the current platform?

~Is there a solution or a possible workaround for this?~

It turns out that Mono.Android only exists in Xamarin.Forms. Unity seems to be using something different (for Android, at least), hence it is unable to find Mono.Android explicitly. I don't think using monoandroid10's dlls will work with Unity for now.

Meanwhile if you use the net461 dlls instead, you get "System.DllNotFoundException: ws2_32.dll" that doesn't exist in Android platforms.

It seems that 32feet is not compatible with Unity-Android implementations for now, unless there is some way to reference Unity's Android components